# randomElement(using:) Returns a random element of the collection, using the given generator as a source for randomness. ``` func randomElement(using generator: inout T) -> Self.Element? where T : RandomNumberGenerator ``` ## Parameters `generator` The random number generator to use when choosing a random element. ## Return Value A random element from the collection. If the collection is empty, the method returns `nil`. ## Discussion Call `randomElement(using:)` to select a random element from an array or another collection when you are using a custom random number generator. This example picks a name at random from an array: ``` let names = ["Zoey", "Chloe", "Amani", "Amaia"] let randomName = names.randomElement(using: &myGenerator)! // randomName == "Amani" ``` > Complexity: O(1) if the collection conforms to > `RandomAccessCollection`; otherwise, O(*n*), where *n* is the length > of the collection. > Note: The algorithm used to select a random element may change in a > future version of Swift. If you’re passing a generator that results in > the same sequence of elements each time you run your program, that > sequence may change when your program is compiled using a different > version of Swift. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)